We examined if administration of very low-density lipoproteins (VLDL) to pregnant rats increases surfactant phosphatidylcholine (PtdCho) content in fetal pre-type II alveolar epithelial cells. VLDL-triglycerides are hydrolyzed to fatty acids by lipoprotein lipase (LPL), an enzyme activated by heparin. Fatty acids released by LPL can incorporate into the PtdCho molecule, or activate the key biosynthetic enzyme, cytidylyltransferase (CCT). Dams were given bovine serum albumin (BSA), heparin, VLDL, or VLDL with heparin intravenously. Radiolabeled VLDL given to the pregnant rat crossed the placenta, distributed systemically in the fetus, and incorporated into disaturated PtdCho (DSPtdCho) within pre-type II cells. Maternal administration of VLDL with heparin increased DSPtdCho content in cells by 45% compared to control (p<0.05). VLDL produced a dose-dependent, saturable, and selective increase in CCT activity. VLDL did not significantly alter immunoreactive CCT content but increased palmitic, stearic, and oleic acids in pre-type II cells. Further, hypertriglyceridemic Apo E knockout mice contained significantly greater levels of DSPtdCho content in alveolar lavage and CCT activity compared to either LDL receptor knockout mice or wild-type controls that have normal serum triglycerides. Thus, the nutritional or genetic modulation of serum VLDL- triglycerides provides specific fatty acids that stimulate PtdCho synthesis and CCT activity thereby increasing surfactant content.